gecko-dev/layout/generic/nsIAnonymousContentCreator.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* interface for rendering objects that manually create subtrees of
* anonymous content
*/
#ifndef nsIAnonymousContentCreator_h___
#define nsIAnonymousContentCreator_h___
#include "nsQueryFrame.h"
#include "nsIContent.h"
#include "nsStyleContext.h"
#include "nsTArrayForwardDeclare.h"
class nsBaseContentList;
class nsIFrame;
/**
* Any source for anonymous content can implement this interface to provide it.
* HTML frames like nsFileControlFrame currently use this.
*
* @see nsCSSFrameConstructor
*/
class nsIAnonymousContentCreator
{
public:
NS_DECL_QUERYFRAME_TARGET(nsIAnonymousContentCreator)
struct ContentInfo {
ContentInfo(nsIContent* aContent) :
mContent(aContent)
{}
ContentInfo(nsIContent* aContent, nsStyleContext* aStyleContext) :
mContent(aContent), mStyleContext(aStyleContext)
{}
nsIContent* mContent;
nsRefPtr<nsStyleContext> mStyleContext;
};
/**
* Creates "native" anonymous content and adds the created content to
* the aElements array. None of the returned elements can be nullptr.
*
* If the anonymous content creator sets the editable flag on some
* of the elements that it creates, the flag will be applied to the node
* upon being bound to the document.
*
* @note The returned elements are owned by this object. This object is
* responsible for calling UnbindFromTree on the elements it returned
* from CreateAnonymousContent when appropriate (i.e. before releasing
* them).
*/
virtual nsresult CreateAnonymousContent(nsTArray<ContentInfo>& aElements)=0;
/**
* Appends "native" anonymous children created by CreateAnonymousContent()
* to the given content list depending on the filter.
*
* @see nsIContent::GetChildren for set of values used for filter.
*/
virtual void AppendAnonymousContentTo(nsBaseContentList& aElements,
uint32_t aFilter) = 0;
/**
* Implementations can override this method to create special frames for the
* anonymous content returned from CreateAnonymousContent.
* By default this method returns nullptr, which means the default frame
* is created.
*/
virtual nsIFrame* CreateFrameFor(nsIContent* aContent) { return nullptr; }
};
#endif